Tiêu chuẩn ASTM a350 a350m 02 ;QTM1MC9BMZUWTS1SRUQ

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.

Designation: A 350/A 350M – 02b4

Standard Specification for

Carbon and Low-Alloy Steel Forgings, Requiring Notch
Toughness Testing for Piping Components1
This standard is issued under the fixed designation A 350/A 350M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.

1
This specification is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.22
on Steel Forgings and Wrought Fittings for Piping Applications and Bolting Materials for Piping and Special Purpose Applications.
Current edition approved Sept. 10, 2002. March 1, 2004. Published November 2002. April 2004. Originally published as A 350 – 52 T. approved in 1952. Last previous
edition approved in 2002 as A 350/A 350M – 02ab.

Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.

1


A 350/A 350M – 02b4
1. Scope*
1.1 This specification2 covers several grades of carbon and low-alloy steel forged or ring-rolled flanges, forged fittings and
valves intended primarily for low-temperature service and requiring notch toughness testing. They are made to specified
dimensions, or to dimensional standards, such as the ASME and API Specifications referenced in Section 2. Although this

specification covers some piping components machined from rolled bar and seamless tubular materials (see 5.3.3), it does not cover
raw material produced in these product forms.
1.2 No limitation on size is intended beyond the ability of the manufacturer to obtain the specified requirements. However, Class
3 of Grade LF787 is only available in the quenched-and-precipitation heat treated condition.
1.3 Supplementary requirements are provided for use when additional testing or inspection is desired. These shall apply only
when specified by the purchaser in the order.
1.4 This specification is expressed in both inch-pound units and in SI units. However, unless the order specifies the applicable
“M” specification designation (SI units), the material shall be furnished to inch-pound units.
1.5 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units
are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used
independently of the other. Combining values from the two systems may result in nonconformance with the specification.
NOTE 1—Refer to Test Methods and Definitions A 370 for notes on significance of notched-bar impact testing.

2. Referenced Documents
2.1 ASTM Standards: 3
A 370 Test Methods and Definitions for Mechanical Testing of Steel Products
A 788 Specification for Steel Forgings, General Requirements
A 961 Specification for Common Requirements for Steel Flanges, Forged Fittings, Valves, and Parts for Piping Applications
2.2 ASME Standards:
B 16.5 Steel Pipe Flanges and Flanged Fittings4
B 16.9 Factory-Made Wrought Steel Butt-Welding Fittings4
B 16.10 Face-to-Face and End-to-End Dimensions of Ferrous Valves4
B 16.11 Forged Steel Fittings, Socket-Welding and Threaded4
B 16.30 Unfired Pressure Vessel Flange Dimensions4
B 16.34 Valves-Flanged, Threaded, and Welding End4
B 16.47 Large Diameter Steel Flanges4
2.3 ASME Boiler and Pressure Vessel Code:
Section IX Welding Qualifications2
2.4 AWS Standards:
A 5.1 Mild Steel Covered Arc-Welding Electrodes5

A 5.5 Low-Alloy Steel Covered Arc-Welding Electrodes5
2.5 API Standards:6
600 Steel Gate Valves with Flanged or Butt-Welding Ends
602 Compact Design Carbon Steel Gate Valves for Refinery Use
605 Large Diameter Carbon Steel Flanges
3. Ordering Information
3.1 It is the purchaser’s responsibility to specify in the purchase order information necessary to purchase the needed material.
In addition to the ordering information guidelines in Specification A 961, orders should include the following information:
3.1.1 Additional requirements (see Table 1 footnotes).
4. General Requirements
4.1 Product furnished to this specification shall conform to the requirements of Specification A 961, including any
supplementary requirements that are indicated in the purchase order. Failure to comply with the general requirements of

2

For ASME Boiler and Pressure Vessel Code applications see related Specification SA-350 in Section II of that Code.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at For Annual Book of ASTM Standards,
Vol 01.03. volume information, refer to the standard’s Document Summary page on the ASTM website.
Annual Book
4
Available from American Society of ASTM Standards, Vol 01.05. Mechanical Engineers (ASME), ASME International Headquarters, Three Park Ave., New York, NY
10016-5990.
Annual Book of ASTM Standards, Vol 01.01.
5
Available from The American Welding Society (AWS), 550 NW LeJeune Rd., Miami, FL 33126.
6
Available from The American Society of Mechanical Engineers (ASME), ASME International Headquarters, Three Park Ave., New York, NY 10016-5990. Petroleum
Institute (API), 1220 L. St., NW, Washington, DC 20005.
3

2


A 350/A 350M – 02b4
TABLE 1 Chemical Requirements
Composition, wt. %
Element
Carbon, max
Manganese
Phosphorus,
max
Sulfur, max
SiliconA
Nickel
Chromium
Molybdenum
Copper
Columbium
Columbium
Vanadium
Nitrogen

Grade LF1

Grade LF2

Grade LF3

Grade LF5

Grade LF6

Grade LF9

0.30
0.60–1.35
0.035

0.30
0.60–1.35
0.035

0.20
0.90 max
0.035

0.30
0.60–1.35
0.035

0.22
1.15–1.50
0.025

0.20
0.40–1.06
0.035

0.07
0.40–0.70

0.025

Grade LF787

0.040
0.15–0.30
0.40 maxB
0.30 maxB,C
0.12 maxB,C
0.40 maxB
0.02 max
0.02 maxD
0.08 max
...

0.040
0.15–0.30
0.40 maxB
0.30 maxB,C
0.12 maxB,C
0.40 maxB
0.02 max
0.02 maxD
0.08 max
...

0.040
0.20–0.35
3.3–3.7
0.30 maxC

0.12 maxC
0.40 maxC
0.02 max
0.02 max
0.03 max
...

0.040
0.20–0.35
1.0–2.0
0.30 maxC
0.12 maxC
0.40 maxC
0.02 max
0.02 max
0.03 max
...

0.025
0.15–0.30
0.40 maxB
0.30 maxB,C
0.12 maxB,C
0.40 maxB
0.02 max
0.02 max
0.04–0.11
0.01–0.030

0.040

...
1.60–2.24
0.30 maxC
0.12 maxC
0.75–1.25
0.02 max
0.02 max
0.03 max
...

0.025
0.40 max
0.70–1.00
0.60–0.90
0.15–0.25
1.00–1.30
0.02 min
0.02 min
0.03 max
...

A

When vacuum carbon-deoxidation is required by Supplementary Requirement S4, the silicon content shall be 0.12 % maximum.
The sum of copper, nickel, chromium, vanadium and molybdenum shall not exceed 1.00 % on heat analysis.
C
The sum of chromium and molybdenum shall not exceed 0.32 % on heat analysis.
D
The sum of chromium and molybdenum shall not exceed 0.32 % on heat analysis.
B

Specification A 961 constitutes nonconformance with this specification. In case of conflict between the requirements of this
specification and Specification A 961, this specification shall prevail.
5. Manufacture
5.1 Melting Process—The steel shall be produced by any of the following primary processes: open-hearth, basic oxygen,
electric-furnace, or vacuum-induction melting (VIM). The primary melting may incorporate separate degassing or refining, and
may be followed by secondary melting using electroslag remelting (ESR), or vacuum-arc remelting (VAR).
5.1.1 The steel shall be fully killed, fine-grain practice.
5.1.2 The molten steel may be vacuum treated prior to or during pouring of the ingot.
5.2 Discard—A sufficient discard shall be made to secure freedom from injurious piping and undue segregation.
5.3 Forging Process:
5.3.1 Material for forgings shall consist of ingots, or forged, rolled, or strandcast blooms, billets, slabs, or bars.
5.3.2 The finished product shall be a forging as defined in the Terminology section of Specification A 788.
5.3.3 Except for flanges of all types, hollow, cylindrically-shaped parts may be machined from rolled bar or seamless tubular
materials provided that the axial length of the part is approximately parallel to the metal flow lines of the stock. Other parts,
excluding flanges of all types, may be machined from hot-rolled or forged bar up through and including NPS4. Elbows, return
bends, tees, and header tees shall not be machined directly from bar stock.
5.4 Heat Treatment:
5.4.1 After hot working and before reheating for heat treatment, the forging shall be allowed to cool substantially below the
transformation range.
5.4.2 Forgings of grades other than Grade LF787 shall be furnished in the normalized, or in the normalized and tempered, or
in the quenched and tempered condition described by the following procedures:
5.4.2.1 Normalize—Heat to a temperature that produces an austenitic structure, holding sufficient time to attain uniform
temperature throughout. Cool uniformly in still air.
5.4.2.2 Normalize and Temper—Subsequent to normalize, reheat to 1100°F [590°C] minimum, holding at temperature a
minimum of 30 min/in. [30 min/25 mm] of maximum thickness, but in no case less than 30 min. Cool in still air.
5.4.2.3 Quench and Temper—The procedure for quenching shall consist of either (1) fully austenitizing the forgings followed
by quenching in a suitable liquid medium or ( 2) using a multiple stage procedure whereby the forging is first fully austenitized
and rapidly cooled, then reheated to partially reaustenitize, followed by quenching in a suitable liquid medium. All quenched
forgings shall be tempered by reheating to a temperature between 1100°F [590°C] and the lower transformation temperature,

holding at temperature a minimum of 30 min/in. [30 min/25 mm] of maximum thickness but in no case less than 30 min. Cool
in still air.
5.4.3 Grade LF787 forgings shall be furnished in either the normalized-and-precipitation heat treated condition or in the
quenched-and-precipitation heat treated condition. The heat treatment procedures shall be as follows:
5.4.3.1 Normalized-and-Precipitation Heat Treated—Heat to a temperature in the range from 1600 to 1725°F [870 to 940°C],
hold at the temperature for a time sufficient to attain uniform temperature throughout, soak at the temperature for not less than 1⁄2
h, and remove from the furnace and cool in air. Subsequently, heat to a temperature in the range from 1000 to 1200°F [540 to
650°C], soak at the temperature for not less than 1⁄2 h, and cool at any convenient rate.
5.4.3.2 Quenched-and-Precipitation Heat Treated—Heat to a temperature in the range from 1600 to 1725°F [879 to 940°C],
hold at the temperature for a time sufficient to attain uniform temperature throughout, soak at the temperature for not less than 1⁄2
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A 350/A 350M – 02b4
h and quench in a suitable liquid medium by immersion; reheat to a temperature in the range from 1000 to 1225°F [540 to 665°C],
hold at the temperature for not less than 1⁄2 h, and cool at any convenient rate.
6. Chemical Composition
6.1 Heat Analysis:
6.1.1 A chemical heat analysis in accordance with Specification A 961 shall be made and conform to the requirements as to
chemical composition prescribed in Table 1. Leaded steels shall not be permitted.
6.1.2 Intentional additions of copper, nickel, chromium or molybdenum to Grades LF1, LF2 or LF6 are permitted only if the
maximum carbon equivalent of Supplementary Requirement S6 is maintained. Intentional additions of copper, chromium or
molybdenum to Grades LF3 or LF5 are not permitted. Intentional additions of chromium or molybdenum to Grade LF9 are not
permitted.
6.2 Product Analysis:
6.2.1 The purchaser may make a product analysis on products supplied to this specification in accordance with Specification
A 961.
7. Mechanical Properties
7.1 Tension Tests:
7.1.1 Requirements—The material shall conform to requirements for tensile properties in Table 2.

7.1.1.1 The test specimen shall be obtained from a rough or finished forging, or prolongation thereof. For forgings under 10 000
lbs, at time of heat treatment, it may be obtained from separately forged test blanks from the same heat of steel as the production
forgings. The test blank shall be reduced by forging in a manner similar to that for the products represented, and shall receive
approximately the same hot working and reduction and the same heat treatment as the finished products represented. The test
material shall be treated in the same furnace at the same time as the forging it represents, subject to the requirements of 7.1.2.1.
7.1.1.2 The test specimen shall represent all forgings from the same heat and heat-treatment load whose maximum thicknesses
do not exceed the thickness of the test forging or blank by more than 1⁄4 in. [6 mm].
7.1.2 Number of Tests—One tension test at room temperature shall be made in accordance with 7.1.1.2 from each heat in each
heat-treatment load.
7.1.2.1 If heat treatment is performed in either a continuous or a batch-type furnace controlled within 625°F [614°C] of the
required heat-treatment temperature and equipped with recording pyrometers so that complete records of heat treatment are
available and if the same heat-treating cycles are used on the forgings represented by the tension test, then one tension test from
each heat shall be required, instead of one tension test from each heat in each heat treatment load in accordance with 7.1.1.2.
7.1.3 Test Locations and Orientations— The test specimen shall be removed from the heaviest section of the forging or test
blank, at locations described in 7.1.3.1, 7.1.3.2, 7.1.3.5 or as close to these locations as practical, subject to forging size and
geometry.
TABLE 2 Tensile Properties at Room TemperatureA
Grades
LF1 and LF5
Class 1

Tensile strength, ksi [MPa]
Yield strength, min, ksi [MPa]B,C
Elongation:
Standard round specimen, or
small proportional specimen,
min % in
4D gage length
Strip specimen for wall thickness
5⁄16 in. [7.94 mm] and over

and for all small sizes tested
in full section; min % in 2 in.
[50 mm]
Equation for calculating min
elongation for strip specimens
thinner than 5⁄16 in. [7.94 mm];
min % in 2 in. [50 mm]
t= actual thickness in inches
Reduction of area, min, %

LF2
Classes
1 and 2

LF3
Classes 1
and 2
LF5
Class 2

LF6

LF9

Class 1

Classes 2
and 3

60–85

[415–585]
30 [205]

70–95
[485–655]
36 [250]

70–95
[485–655]
37.5 [260]

66–91
[455–630]
52 [360]

75–100
[515–690]
60 [415]

25

22

22

22

28

30

30

48t + 13

48t + 15

38

30

LF787
Class 2

Class 3

63–88
[435–605]
46 [315]

65–85
[450–585]
55 [380]

75–95
[515–655]
65 [450]

20

25

20

20

30

28

28

28

28

48t + 15

48t + 15

48t + 13

48t + 13

48t + 13

48t + 13

35

40

40

38

45

45

A

See 7.3 for hardness tests.
B
Determined by either the 0.2 % offset method or the 0.5 % extension under load method.
C
For round specimens only.

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A 350/A 350M – 02b4
7.1.3.1 For forgings or test blanks having a maximum heat-treated thickness, T, of 2 in. [50 mm] or less, the longitudinal axis
of the test specimen shall be taken at mid-thickness and its mid-length shall be at least 2 in. [50 mm] from a second heat treated
surface, exclusive of the T dimension surfaces. (This is normally referred to as 1⁄2 T by 2 in. [50 mm]).
7.1.3.2 For forgings or test blanks having a maximum heat-treated thickness, T, greater than 2 in. [50 mm], the central axis of
the test specimen shall be taken at least 1⁄4 T from the nearest heat-treated surface and at least T or 4 in. [100 mm], whichever
is less, from any second heat-treated surface. For quenched and tempered forgings, the midlength of the test specimen shall be at
least T from any second heat-treated surface. See Fig. 1 for test specimen location in separately forged test blanks for quenched
and tempered forgings.

7.1.3.3 Metal Buffers— The required distances from heat treated surfaces may be obtained with metal buffers instead of integral
expansions. Buffer material may be carbon or low alloy steel, and shall be joined to the forging with a partial penetration weld
that seals the buffered surface. Specimens shall be located at 1⁄2 in. [13 mm] minimum from the buffered surface of the forging.
Buffers shall be removed and the welded areas subjected to magnetic particle test to assure freedom from cracks unless the welded
areas are completely removed by subsequent machining.
7.1.3.4 The test specimen shall have its longitudinal axis located parallel to the direction of major working of the forging or test
blank.
7.1.3.5 With prior purchaser approval, tests may be taken at a depth (t) corresponding to the distance from the area of significant
loading to the nearest heat treated surface and at least twice this distance (2t) from any second surface. However, the test depth
shall not be nearer to one treated surface than 3⁄4 in. [19 mm] and to the second treated surface than 11⁄2 in. [38 mm]. This method
of test location would normally apply to contour-forged parts, or parts with thick cross-sectional areas where 1⁄4 T 3 T testing
(7.1.3.2) is not practical. Sketches showing the exact test locations shall be approved by the purchaser when this method is used.
7.1.4 Test Method—Testing shall be performed in accordance with Test Methods and Definitions A 370. The test specimen shall
be as large as is practicable and shall be machined to the form and dimensions of Fig. 5 of Test Methods and Definitions A 370.
When seamless tubular materials are used, testing shall be performed on longitudinal specimens in accordance with Annex A2,
Steel Tubular Products, of Test Methods and Definitions A 370.
7.2 Impact Test:
7.2.1 Requirements—The material shall conform to the requirements for impact properties in Table 3 when tested at the
applicable standard temperature in Table 4 within the limits of 7.2.4.2 and 7.2.4.3. When subsize specimens are used, the impact
energy values obtained shall conform to Table 5 at energy values proportional to standard size. Exceptions to this requirement are
permissible when Supplementary Requirement S1 is specified by the purchaser. Impact tests may be made at temperatures different
from those in Table 4, provided that the test temperature is at least as low as the intended service temperature, and that the forging
is suitably marked to identify the reported test temperature.
7.2.1.1 The test specimens shall be machined from material obtained as in 7.1.

NOTE 1—For material with thickness T greater than 2 in. [50 mm],
T2= T3= T4$ Tmax
where:
Tmax= maximum heat treated thickness
FIG. 1 Test Specimen Location for Quenched and Tempered

Forgings

5


A 350/A 350M – 02b4
TABLE 3 Charpy V-Notch Energy Requirements for Standard
Size [10 by 10 mm] Specimens
Minimum Impact
Energy Required
for Average of
Each Set of Three
Specimens,
ft·lbf[J]

Grade

LF1 and LF9
LF2, Class 1
LF3, Class 1
LF5 Class 1 and 2
LF787 Classes 2 and 3
LF6, Class 1
LF2, Class 2
LF3, Class 2
LF6, Classes 2 and 3

13
15
15

15
15
15
20
20
20

Minimum Impact
Energy Permitted
for One Specimen
only of a Set,
ft·lbf[J]

[18]
[20]
[20]
[20]
[20]
[20]
[27]
[27]
[27]

10
12
12
12
12
12
15

15
15

[14]
[16]
[16]
[16]
[16]
[16]
[20]
[20]
[20]

TABLE 4 Standard Impact Test Temperature for Standard Size
[10 by 10 mm] Specimens
Grade

Test Temperature, °F [°C]

LF1
LF2 Class 1
LF2 Class 2
LF3, Classes 1 and 2
LF5, Classes 1 and 2
LF6, Classes 1 and 2
LF6, Class 3
LF9
LF787, Class 2
LF787 Class 3

−20 [−29]
−50 [−46]
−0 [−18]
−150 [−101]
−75 [−59]
−60 [−51]
0 [−18]
−100 [−73]
−75 [−59]
−100 [−73]

TABLE 5 Minimum Equivalent Absorbed Energy ft·lbf (J) for
Various Specimen SizesA
Standard
Size [10 by
10 mm]

⁄ size
[10 by
7.5 mm]

⁄ size
[10 by
6.6 mm]

15
13
12
10

12 [16]
10 [14]
10 [14]
8 [11]

10
9
9
7

A

[20]
[18]
[16]
[14]

34

⁄ size
[10 by
5 mm]

23

12

[14]
[12]
[12]

[10]

8 [11]
7 [10]
7 [10]
5 [7]

⁄ size
[10 by
3.3 mm]
13

5
5
4
3

[7]
[7]
[6]
[5]

⁄ size
[10 by
2.5 mm]
14

4
4
3

3

[6]
[6]
[5]
[5]

Straight-line interpolation for intermediate values is permitted.

7.2.2 Number of Tests—Three specimens shall constitute one test set. There shall be the same number of test sets as tension tests
in 7.1.2.
7.2.3 Test Locations and Orientations— The test specimen shall be located and oriented as described in 7.1.3. The area under
the notch of the impact test specimen shall be used to locate the specimen with respect to the second heat-treated surface. The base
of the notch shall be perpendicular to the nearest heat-treated surface.
7.2.4 Test Method—The notched bar impact test shall be made in accordance with the procedure for the Charpy V-notch type
test as described in Test Methods and Definitions A 370.
7.2.4.1 Standard size specimens shown in Fig. 11 of Test Methods and Definitions A 370 shall be used for the impact test. Where
the material is of insufficient thickness, or the shape of the forging precludes standard size, the largest obtainable subsize specimen
described in Test Methods and Definitions A 370 shall be used.
7.2.4.2 Where subsize specimens are used and represent forged material with thicknesses equal to or greater than 0.394 in. [10
mm], and where the largest obtainable specimen has a width along the notch of at least 8 mm, such specimen shall be tested at
the temperature in Table 4. Where the largest obtainable specimen has a width along the notch less than 8 mm, the temperature
for testing shall be lower than the temperature in Table 4 by the amount shown in Table 6 for the actual specimen width tested.
7.2.4.3 Where subsize specimens are used and represent forged material with thicknesses less than 0.394 in. [10 mm], and where
the largest obtainable specimen has a width along the notch of at least 80 % of the forging thickness, the specimen shall be tested
at the temperature in Table 4. Where the largest obtainable specimen has a width along the notch of less than 80 % of the material
thickness, the temperature for testing shall be lower than the temperature in Table 4 by an amount equal to the difference (referring
to Table 6) between the temperature reduction corresponding to the thickness of the material represented, and the temperature
reduction corresponding to the specimen width actually tested.
7.3 Hardness Test:

6


A 350/A 350M – 02b4
TABLE 6 Charpy Impact Test Temperature Reduction Below
Table 5 Test Temperature when the Subsize Charpy Impact Width
along Notch is Less than 80% of the Forging Thickness

Size of Bar

Standard
Standard
Standard
3⁄4-size
3⁄4-size
2⁄3-size
2⁄3-size
1⁄2-size
1⁄2-size
1⁄3-size
1⁄3-size
1⁄4-size
A

Thickness of the
Material Represented
(see 7.2.4.3), or
Charpy, Impact
Specimen Width Along
the NotchA, in. [mm]

Temperature
Reduction,
° F [°C]

0.394 [10]
0.354 [9]
0.315 [8]
0.295 [7.5]
0.276 [7]
0.262 [6.67]
0.236 [6]
0.197 [5]
0.158 [4]
0.131 [3.33]
0.118 [3]
0.099 [2.5]

0 [0]
0 [0]
0 [0]
5 [3]
8 [5]
10 [6]
15 [8]
20 [11]
30 [17]
35 [20]
40 [22]
50 [28]

Straight-line interpolation for intermediate values is permitted.

7.3.1 Except when only one forging is produced, a minimum of two forgings shall be hardness tested per batch or continuous
run as defined in 7.1.2.1 to ensure that hardness of the forgings does not exceed 197 HB after heat treatment for mechanical
properties. The hardness measurements shall be made in accordance with Test Methods and Definitions A 370. When only one
forging is produced, it shall be hardness tested to ensure that it meets the 197 HB maximum of this specification. The purchaser
may verify that this requirement has been met by testing at any location on the forging, provided that such testing does not render
the forging useless.
8. Hydrostatic Test
8.1 Forgings manufactured under this specification shall be capable of passing a hydrostatic test compatible with the rating of
the finished item. Such tests shall be conducted by the manufacturer only when Supplementary Requirement S57 of Specification
A 961 is specified.
9. Workmanship, Finish, and Appearance
9.1 Forgings shall conform to the requirements of Specification A 961.
10. Retests
10.1 If any test specimen shows flaws or defective machining, it may be discarded and another specimen substituted.
11. Rework and Retreatment
11.1 If the results of the mechanical tests do not conform to the requirements specified, the manufacturer may reheat treat the
forgings represented, and shall retest to the applicable requirements.
11.2 Individually tested forgings meeting all requirements shall be acceptable.
11.3 Repair by Welding—Weld repairs shall be permitted (see Supplementary Requirement S58 of Specification A 961) at the
discretion of the manufacturer with the following limitations and requirements:
11.3.1 Repair by welding shall be made using welding procedures and welders qualified in accordance with ASME Section IX
of the Code. The weld procedure qualification test shall also include impact tests of the weld metal and heat-affected zone. All
impact test specimens shall have the longitudinal axis transverse to the weld and the base of the notch normal to the weld surface.
Weld specimens shall have the notch in weld metal and heat-affected zone specimens shall have the notch in the heat-affected zone.
The specimens shall be as large as permitted by the weldment thickness. Where full-size specimens can be obtained and where
there is sufficient weldment thickness, the weld specimen shall be taken with one side of the specimen within 1⁄16 in. [1.6 mm] of
the weld surface. Heat-affected zone impact test specimens shall be taken at the same depth and locations applicable to the forging

in 7.1.3.1 and 7.1.3.2. When forgings are thermally treated after repair welding, the weld procedure test plate shall be subjected
to the same thermal treatment. The mechanical properties of the weld procedure qualification test shall conform to Section 7.
11.3.2 Defects shall be completely removed by chipping or grinding to sound metal as verified by magnetic particle, or liquid
penetrant inspection prior to welding.
11.3.3 For Grade LF1 forgings, and LF2 forgings that are to be only stress-relieved after repair welding, the weld metal shall
be deposited using carbon steel electrodes E 7015, E 7016, or E 7018, complying with AWS A 5.1. For Grade LF2 forgings in all
other conditions of post-weld heat treatment, the weld metal shall be deposited using low-alloy steel electrodes E 7015-A1;
E 7016-A1, or E 7018-A1 complying with AWS 5.5; for Grade LF3 forgings the weld metal shall be deposited using low-alloy
steel electrodes E 8016-C2 or E 8018-C2 complying with AWS A 5.5; for Grades LF5, LF9, and LF787 forgings, the weld metal
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A 350/A 350M – 02b4
shall be deposited using low-alloy steel electrodes E 8016-C1 or E 8018-C1 complying with AWS A 5.5. For Grade LF6, the
electrodes shall be low-hydrogen, E-XX15, E-XX16, or E-XX18 complying with AWS A 5.1 or A 5.5, as applicable.
11.3.4 After repair welding, the area welded shall be completely free of defects as verified by magnetic particle or liquid
penetrant inspection.
11.3.5 Forgings repair welded in the normalized, normalized and tempered, or the quenched and tempered conditions shall be
stress-relieved after repair welding at 1100°F [590°C] minimum, but not higher than the temperature previously used for tempering
the base metal of the same forging, or shall be reheat treated in accordance with 5.4.
11.3.6 When the purchaser specifies Supplementary Requirement S5, the same requirements shall apply to the weld procedure
qualification tests.
11.3.7 Repair by welding shall not exceed 10 % of the surface area of the forging or 331⁄3 % of the wall thickness of the finished
forging, or 3⁄8 in. [9.5 mm], whichever is less, without prior approval of the purchaser.
11.3.8 When approval of the purchaser is obtained, the limitations set forth in 11.3.7 may be exceeded, but all other
requirements of 11.3 shall apply.
12. Inspection
12.1 Inspection provisions of Specification A 961 shall apply.
13. Rejection and Rehearing
13.1 Purchaser shall comply with provisions of Specification A 961.

14. Certification
14.1 For forgings made to specified dimensions when agreed to by the purchaser, and for forgings made to dimensional
standards, application of identification marks as required in Section 15 shall be the certification that the forgings have been
furnished in accordance with the requirements of this specification.
14.2 When test reports are required, they shall include certification that all requirements of this specification have been met, and
shall be traceable to the forging represented. The specification designation included on test reports shall include year of issue and
revision letter, if any. The manufacturer shall provide the following where applicable:
14.2.1 Type heat treatment, Section 5,
14.2.2 Chemical analysis results, Section 6 (Table 1),
14.2.3 Product analysis results, 6.2 (Table 1),
14.2.4 Tensile property results, Section 7 (Table 2) report the yield strength and ultimate strength, in ksi [MPa], elongation and
reduction in area, in percent,
14.2.5 Impact test results, 7.2 (Table 3, Table 4, Table 5, and Table 6),
14.2.6 Hardness results, 7.3.1,
14.2.7 Any supplementary testing required by the purchase order, and
14.2.8 If repaired by welding, letter W is to follow the ASTM designation.
15. Product Marking
15.1 In addition to the marking requirements of Specification A 961, manufacturer’s name (see Note 2) or symbol shall be
permanently marked on each forging.
NOTE 2—For purposes of identification marking, the manufacturer is considered the organization that certifies the piping component was manufactured,
sampled, and tested in accordance with this specification and the results have been determined to meet the requirements of this specification.

15.1.1 If the forgings have been quenched and tempered or quenched-and-precipitation heat treated, the letters QT shall be
stamped on the forgings following the ASTM designation.
15.1.2 Forgings repaired by welding shall be marked with the letter W following the ASTM designation.
15.2 If identification stamps are objectionable and detrimental to the forging, and when so stated on the purchase order, the
marks may be painted or stenciled on the forging, or stamped on a metal or plastic tag which shall be securely attached to the
forging.
15.3 When test reports are required, additional marks shall be used as necessary to identify the part with the test report.
15.4 If the test temperature is other than the standard temperature specified in Table 4, the mark shall also include the suffix letter

S to the grade and class and the test temperature. A prefix 0 to the test temperature shall indicate a less than 0°F [-18°C] value.
For example, LF2S 0175 denotes a test temperature of –175°F [-115°C] for an LF2 part.
15.5 Parts meeting all requirements for more than one class may be marked with more than one class such as LF2 CL1/C12;
LF5 CL1/CL2, and so forth.
15.6 Bar Coding—In addition to the requirements in 15.1, 15.2, 15.3, 15.4, and 15.5, bar coding is acceptable as a supplemental
identification method. The purchaser may specify in the order a specific bar coding system to be used. The bar coding system, if
applied at the discretion of the supplier, should be consistent with one of the published industry standards for bar coding. If used
on small parts, the bar code may be applied to the box or a substantially applied tag.
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A 350/A 350M – 02b4
16. Keywords
16.1 carbon equivalent; pipe fittings, steel; piping applications; pressure containing parts; steel flanges; steel forgings, alloy;
steel forgings, carbon; steel valves; temperature service applications, low

SUPPLEMENTARY REQUIREMENTS
In addition to any supplementary requirements of Specification A 961, the following supplementary
requirements shall apply only when specified by the purchaser in the order:
S1. Other Impact Test Temperatures
S1.1 Impact test temperatures lower or higher than the standard temperature in Table 4 of this specification shall be used.
S1.1.1 When higher test temperatures are employed, the actual test temperature may not be higher than that given in Table
S1.1.1.
S1.2 The test temperature shall be specified by the purchaser. When subsize specimens are used, the manufacturer shall adjust
the test temperature in accordance with the size restrictions of 7.2.4.2 and 7.2.4.3.
S1.3 The forging shall be marked with the specified test temperature in accordance with 15.4. A lower temperature shall not be
marked on the forging because of the use of subsize specimens.
S1.4 The test results shall comply with Table 3 for standard size specimens, and with Table 5 for subsize specimens.
S2. Stress-Relieved Test Specimens
S2.1 The test specimens shall be stress relieved. Stress relieving shall be done after heat treatment in 5.4 and before machining

the specimens from the heat-treated test material.
S2.2 The purchaser shall furnish the forging manufacturer with details of the stress-relief treatment desired.
S3. Lateral Expansion
S3.1 Lateral expansion of the Charpy V-notch test in accordance with Section 25 of Test Methods and Definitions A 370 shall
be measured and reported.
S4. Vacuum Carbon-Deoxidized Steels
S4.1 Material made to Grades LF1, LF2, LF3, LF5, and LF9 shall be vacuum carbon-deoxidized, in which case the silicon
content shall be 0.12 % maximum. The test report shall indicate that the steel was vacuum carbon-deoxidized.
S5. Special Impact Test Requirements for Flanges (Note S5.1)
S5.1 Charpy test specimens shall be cut from an actual flange representing each size, heat, and heat-treatment lot. If more than
one size flange is represented by the same heat and heat-treatment lot, the maximum size flange shall be considered representative.
S5.2 The number, location, and orientation of the test specimens shall be stated on the order.
S5.3 The test results shall comply with Table 3 for standard size specimens, and with Table 5 for subsize specimens.
NOTE S5.1—These special requirements should be considered for services when the applied stresses approach the maximum permissible limits of the
governing code, or the installation is subject to severe cyclic conditions (7000 or more cycles over the expected life of the installation), or both.

S6. Carbon Equivalent
S6.1 The maximum carbon equivalent based on heat analysis shall be as shown in Table S6.1.
S6.2 Determine the carbon equivalent (CE) as follows:
CE = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15
TABLE S1.1.1 Maximum Supplemental Test Temperatures
Grade

Maximum Test Temperature, °F [°C]

LF1
LF2, Class 1
LF3, Classes 1 and 2
LF5, Classes 1 and 2
LF6, Classes 1 and 2

LF9
LF787, Class 2
LF787, Class 3
LF2 Class 2
LF6 Class 3

−10 [−23]
−35 [−37]
−125 [−87]
−60 [−51]
−40 [−40]
−80 [−62]
−60 [−51]
−80 [−62]
+10 [−12]
+10 [−12]

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A 350/A 350M – 02b4
TABLE S6.1 Maximum Carbon Equivalent Value
Grade
LF1
LF2 CL1 and CL2
LF6 CL1
LF6 CL2

Max.Thickness Less
Than or Equal to 2 in.

Max. Thickness
Greater Than 2 in.

0.45
0.47
0.45
0.47

0.46
0.48
0.46
0.48

S6.3 A lower maximum carbon equivalent may be agreed upon between the supplier and the purchaser.

SUMMARY OF CHANGES
Committee A01 has identified the location of selected changes to this standard specification since the last issue
(, A 350/A 350M – 02a)b, that may impact the use of this stpecification. (Approved Mard.ch 1, 2004)
(1) Revised Grades LF1 and LF2 in Table 1 to allow higher Cb by agreement.

Committee A01 has identified the location of selected changes to this specification since the last issue, A 350/A 350M – 02a,
that may impact the use of this specification. (Approved Sept. 10, 2002)
(1) Revised Tables 2-4, and Tables S1.1.1 and S6.1 to clarify Classes of LF2 and LF3.
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